Some downhole oil field tools include accumulators for holding gas under pressure, the gas pressure being used after the tool is run downhole to actuate one or more tool elements. When an accumulator is used as a part of a downhole oil field tool, it is often desirable to alter the charge pressure of the accumulator while the tool is downhole so that the tool will not have to be brought to the surface for the changing of the charge pressure of the accumulator. Bringing the tool to the surface for recharging of the accumulator at a different pressure would involve a so-called round trip, that is, pulling of the drill string or other pipe from the well, recharging the accumulator at the surface, and then rerunning the tool and drill string back into the well hole. This invention seeks to provide an accumulator recharge valve the use of which will permit recharging of the accumulator while the tool is downhole in the well.